Hard Milling Research Papers - Academia.edu (original) (raw)

Hard milling of hardened steel has wide application in mould and die industries. However, milling induced surface finish has received little attention. An experimental investigation is conducted to comprehensively characterize the surface roughness of AISI D2 hardened steel (58-62 HRC) in end milling operation using TiAlN/AlCrN multilayer coated carbide. Surface roughness (R a ) was examined at different cutting speed (v) and radial depth of cut (d r ) while the measurement was taken in feed speed, V f and cutting speed, V c directions. The experimental results show that the milled surface is anisotropic in nature. Surface roughness values in feed speed direction do not appear to correspond to any definite pattern in relation to cutting speed, while it increases with radial depth-of-cut within the range 0.13-0.24 µm. In cutting speed direction, surface roughness value decreases in the high speed range, while it increases in the high radial depth of cut. Radial depth of cut is the most influencing parameter in surface roughness followed by cutting speed.

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- Surface Roughness, Hard Milling

This paper study the effect of three different numerical cutting parameters on surface roughness using during high speed machining. This experiment was carried out to investigate the effect machining parameters of AISI D2 tool steel using an insert end mill. The experiment work plan was carried out using Box-Behken techniques, a part of response surface methodology (RSM) approach. The effect of variable milling cutting parameters were studied to evaluate their effects on surface roughness. In this study, the cutting speed, feed rate, depth of cut and width of cut were in the range of 100-150 m/min, 0.1-0.2 mm/tooth, 0.2 mm and 2.0-8.0 mm respectively. The effect of input factors that on the responds were identified by using mean of ANOVA. The responds of surface roughness then simultaneously optimized. The validation of the test reveals the model accuracy 9%.

Surface topography plays an important part in understanding the nature of machined surfaces. This study is focused on surface topography of AISI D2 hardened steel (58-62 HRC) under dry milling process. Roughness, surface morphology and defects analysis were investigated. This study achieved R a in range of 0.18 to 0.30 µm which is acceptable in mould and die requirement. Moreover, surface roughness decreased as cutting speed increased. From the optical microscope observation shows that the milled surface is anisotropic in nature. The lay pattern is produced by the combination of tool movement during milling operation (cutting and feed speed directions). Meanwhile, the AFM images indicated that the milled surfaces are groovy constructed by low-amplitude topography (between peak and valley of the machined surface waves). Surface defects were found in this study were debris, groove and cavity, all of which affected the surface roughness value.

- by Mohd Amri Lajis
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- Surface topography, Hard Milling

Majority of the published research works on modeling of tool life in machining of hardened steels are based mainly on the turning process, whilst the hard milling process has rarely been adopted. This work is aimed to determine the optimum cutting conditions leading to maximum tool life in end miling of AISI D2 hardened steel using PVD TiAlN coated carbide tool inserts using first and second order models. Analysis of variance (ANOVA) has been conducted for both the models to check the adequacy levels. It has been found that the models are valid for predicting the tool life in machining under specified condition with an average of error less than 10%.

This paper presents the results of experimental investigation conducted on a vertical machining centre (VMC) to ascertain the effectiveness of TiAlN/AlCrN multilayer coated carbide inserts in end milling of AISI D2 hardened steel (58-62 HRC) In high-speed dry hard milling, different cutting speed (v) and radial depth of cut (d r ) were applied. Tool failure modes and wear mechanisms were examined at various cutting parameters. Flank wear, chipping and breakage at cutting edge were found to be the predominant tool failure for the cutting tools. Built-up edge, adhesion and abrasive are the wear mechanisms observed on the cutting tools. The highest volume of material removed, VMR attained was 1500 mm 3 , meanwhile the highest tool life (T) was 4.97 min. The surface roughness, R a values from 0.20 to 0.45 µm can be attained in the workpiece with a high volume material removed. The relationship of tool wear performance and surface integrity was established to lead an optimum parameter in order to have high volume material removed, maximum tool life as well as acceptable surface finish.

- by Mohd Amri Lajis
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- Hard Milling

This paper presents the results of experimental investigation conducted on a vertical machining centre (VMC) to ascertain the effectiveness of TiAlN/AlCrN multilayer coated carbide inserts in end milling of AISI D2 hardened steel (58-62 HRC) In high-speed dry hard milling, different cutting speed (v) and radial depth of cut (d r) were applied. Tool failure modes and wear mechanisms were examined at various cutting parameters. Flank wear, chipping and breakage at cutting edge were found to be the predominant tool failure for the cutting tools. Built-up edge, adhesion and abrasive are the wear mechanisms observed on the cutting tools. The highest volume of material removed, VMR attained was 1500 mm 3 , meanwhile the highest tool life (T) was 4.97 min. The surface roughness, R a values from 0.20 to 0.45 µm can be attained in the workpiece with a high volume material removed. The relationship of tool wear performance and surface integrity was established to lead an optimum parameter in order to have high volume material removed, maximum tool life as well as acceptable surface finish.

- by K Kamdani
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- Advanced Materials, Hard Milling

This study presents experimental results of machined surface integrity of die material (AISI D2 hardened steel) when hot machining (induction heating) assisted end milling using coated carbide is applied. The aim of this work was to study the influence of induction heating temperature, cutting speed, and feed on the effects induced by hard milling on surface integrity (microhardness and work-hardening). Microhardness was measured to observe the distribution of the hardness beneath the surface and to determine the effect of induction heating on the micro-hardness distribution and work-hardening phenomena. The behaviour of microhardness induced in the subsurface region when end milling under room and induction heating cutting conditions using coated carbide inserts was also investigated. The surface integrity and subsurface alteration have been investigated by employing scanning electron microscope (SEM) and Vickers microhardness tester.

- by Mohd Amri Lajis
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- Surface integrity, Hot Machining, Hard Milling

In this paper an attempt has been made to investigate the performance of an electrode made through powder metallurgy (PM) of copper tungsten during electrical discharge machining (EDM). Experimental results are presented on electrical discharge machining of AISI D2 hardened steel in kerosene with a copper tungsten (Cu35% -W65%) tool electrode made through PM method with a constant duty factor of 80%. In terms of high performance EDM process, higher peak current (>20A) and pulse duration (>400µs) with a high machining efficiency were applied. Experimental results have shown that machining at a peak current of 40A and pulse duration of 400µs yields the highest material removal rate (MRR) whereas machining at a peak current of 20A and pulse duration of 400µs yields the lowest tool wear rate (TWR). The surface characteristics of workpiece machined surface become more severe when shorter pulse duration be used at the constant duty factor. The optimum machining performance can be performed by the combination of pulse duration and peak current at 400µs and 40A respectively since the effect of TWR is so small at the varied parameters even at the highest MRR.

- by Mohd Amri Lajis
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- Surface characterization, Hard Milling

- by Mohd Amri Lajis
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- Optimization (Mathematics), Mathematical Modelling, Hard Milling

This paper presents the results of experimental investigation conducted on a vertical machining centre (VMC) to ascertain the effectiveness of TiAlN/AlCrN multilayer coated carbide inserts in end milling of AISI D2 hardened steel (58-62 HRC) In high-speed dry hard milling, different cutting speed (v) and radial depth of cut (dr) were applied. Tool failure modes and wear mechanisms were examined at various cutting parameters. Flank wear, chipping and breakage at cutting edge were found to be the predominant tool failure for the cutting tools. Built-up edge, adhesion and abrasive are the wear mechanisms observed on the cutting tools. The highest volume of material removed, VMR attained was 1500 mm3, meanwhile the highest tool life (T) was 4.97 min. The surface roughness, Ra values from 0.20 to 0.45 μm can be attained in the workpiece with a high volume material removed. The relationship of tool wear performance and surface integrity was established to lead an optimum parameter in order to have high volume material removed, maximum tool life as well as acceptable surface finish.

- by Mohd Amri Lajis
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- Hard Milling

This paper proposes a multi-criteria optimization technique using the mathematical models developed by the response surface methodology (RSM) for the target responses combined with desirability indices for the determining the optimum cutting parameters in end milling of AISI D2 hardened steels. Different responses may require different targets either being maximized or minimized. Simultaneous achievement of the optimized (maximum or minimum) values of all the responses is very unlikely. In machining operations tool life and volume metal removed are targeted to be maximized whereas the machined surface roughness need to be at minimum level. Models showing the combined effect of the three control factors such as cutting speed, feed, and depth of cut are developed. However, a particular combination of parameter levels appears to be optimum for a particular response but not for all. Thus adoption of the method of consecutive searches with higher desirability values is found to be appropriate. In this study the desirability index reaches to a maximum value of 0.889 after five consecutive solution searching. At this stage, the optimum values of machining parameters -cutting speed, depth of cut and feed were determined as 44.27 m/min, 0.61 mm, 0.065 mm/tooth respectively. Under this set condition of machining operations a surface roughness of 0.348 µm and volume material removal of 7.45 cm 3 were the best results compared to the rest four set conditions. However, the tool life would be required to compromise slightly from the optimum value.

- by Mohd Amri Lajis
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- Multiple Criteria Optimization, Hard Milling

As a widely used material in aerospace and medical industry, Ti6Al4V titanium alloy is regarded as difficult-to-machine. In this study, aCN/TiAlN coating was deposited on carbide cutting tools as an attempt to increase the machinability of this alloy. Wear behavior and cutting performance of the aCN/TiAlN coated carbide tools in face milling of Ti6Al4V were investigated under dry conditions. The effect of coating on cutting forces, chip formation and surface integrity of the workpiece with regard to surface finish was investigated. Mechanical and tribological properties of coated samples were characterized by nanoindentation, scratch test, 3D-profilometer, confocal microscope and pin-on-disk test. SEM was employed in combination with EDS for structural and compositional characterization of worn samples. According to the results, abrasive and adhesive wear are dominant tool failures on the coated tools. Higher wear resistance and ~15% longer lifetime were obtained with aCN/TiAlN coated carbide tools in milling of Ti6Al4V. The coating proved to be effective on chip formation and workpiece surface finish. Due to its superior properties in terms of adhesion, wear resistance, surface finish and chip formation, aCN/TiAlN coating is a good candidate for use in face milling of Ti6Al4V alloy.

- by Halil Caliskan
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- Materials Engineering, Materials Science, Metallurgy, Machining

Thin hard coatings are widely used in the protection of cutting tools, dies and molds to prolong their wear resistance and lifetime. Superior properties of different coatings can be combined with multilayer design, and especially a higher microhardness can be obtained by nanocomposite structures. In this study, a multilayer design composing of TiAlSiN, TiSiN and TiAlN layers was applied on carbide cutting tools. The top TiAlSiN layer has a nanocomposite structure of crystalline fcc-TiAlN and amorphous Si3N4 phases. The multilayer nanocomposite TiAlSiN/TiSiN/TiAlN coating was deposited on the carbide cutting tool using an industrial magnetron sputtering system. Wear behavior of the coated tools was investigated in the milling of hardened AISI D2 steel (~55 HRc). The changes in tool wear and surface roughness as a function of cutting distance were recorded. Wear mechanisms and types were investigated using optical and scanning electron microscopy in combination with energy dispersive ...

- by Celil Celil
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- Engineering, Technology, Nano, Tool wear

- by Md.Nurul Amin
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- Advanced Materials, Surface integrity, Microhardness, Hot Machining

This paper focuses on determination of optimum cutting conditions for the efficient hard milling performance of the selected process parameters using hybrid method of response surface methodology and evolutionary computing approaches. A central composite rotatable design is used to design the experimentations. The responses of cutting temperature, tool wear and metal removal rate are measured and analysed the data to develop the mathematical models. The adequacies of the models are tested at 95% confidence level. To achieve the set goal of this study, genetic and simulated annealing algorithms are used for predicting and optimizing the process parameters. The result shows that the simulated annealing algorithm is effectively produced better optimal solutions than the genetic algorithm. The actual experimental results were in agreement with the prediction.

- by IJA ERA
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- Genetic Algorithms, Simulated Annealing, Tool wear, Gentic algorithm optimization